Headers for TBI

[randy88k5]

I have an 88 Blazer, 350 TBI, 700R4, w/ AC, A.I.R, and O2 sensor. Headers seem to be a bit hard to find. Is anyone running headers for this combo, or do you know of any that would work? Brand? Part #? Thanks
-Randy

 

[ryoken]

Thorley has off the shelfs with AIR and O2.... Hooker Comps too...

 

[Thunder]

Edelbrock TES (tublar exhaust system) Its headers and a Y pipe system that hooks up to the stock exhaust. 50 state smog legal

 

[jjlaughner]

Thorley has off the shelfs with AIR and O2.... Hooker Comps too...

they get specific on their listings...
73-91 283-400Blazer, Jimmy. With heat riser. 4"-6" lift kit. 4WD.THY-364Y8
BUT they also have
73-91 283-400Blazer, Jimmy. With heat riser. 3" CAT. 4WD.THY-364Y6
But not 4-6" lift and 3" converter...

http://www.thorleyheaders.com/gm_headers.html

The exhaust I'm getting ready to do is the Magnaflow 3" cat and 3" Flowmaster SUV muffler and this little guy...

to make my own Y-pipe off the stock manifolds

edit added
http://store.summitracing.com/default.asp?target=esearch.asp&N=100&Ntk=PartSearch&Ntt=364Y10

OUCH! $520 and it only has a 2.5" pipe for the part number DTE-364Y10-DA which is supposted to be the 3" cat with heat riser for 4-6" lifted burbs with one AIR fitting on each side...

 

[foxman]

I ran the regular carburated headers.

I just cut off one ear from the AC bracket and welded an o2 bung to the collector and tapped it with a spark plug thread chaser, has worked great for 1/2 the price.

needed to use a steel tube for the remaining ear on the AC bracket as a spacer but ground dwn the bracket nicely and it looks likle factory...

just an idea

jeremy

 

[ryoken]

yeah, Thorleys apps get kinda specifac.. i assume the dif in the 4" to 6" vs stock is the y-pipe..

i was about to do mine recently but x-mas kinda slowed that down... the Thorleys have 1 or 4 AIR tubes available but when i called Holley, they only have our truck in 4 AIR now. i want the single.. and only in comps, not super comps.. said they wheren't making supers for our app anymore...

i want some that are highend and tough. i've even considered SS, from either Thorley or Stans.. even checked into buying Hooker ceramics from Jethot directly.. but as it sits now, i'm looking at the Thorleys in ceramic.. tho i still wanna run dual 2 1/4 with x-over, highflows and 40's or Magnaflows.. looking at about $900, with the Thorleys at $420..

not sure if my exhaust guy gets magnaflows... i could just supply em i suppose... what Magnaflows would you recommend for dual 2 1/4's with a small block?

 

[tx_sub]

Tes

FYI, the edelbrock TES headers make spark plug access hell.

 

[dirtwarrior17]

I have an 88 with a 77 350 block and a holley tbi makin over 400hp with flowtech afterbuners. They are the best cheap header you can buy. combonation between a big tube header and a tri-y header with easy spark plug access. couple bolts are a bitch to get in tho.

 

[Ruthven13]

I just put a set of Thorley ceramics on my truck. It hasn't run yet, but the fit was excellent. Spark plug access was really good, but I do have angle plug heads. No other clearence issues I have come across. I do remember having to put the driver side one in from the bottom though....

 

[dyeager535]

Any of the high end ones you have looked at come with ceramic coated insides?

I remember that being a huge deal a few years back, kept a TON of heat out of the engine bay, but it seems like the idea kind of died out. Perhaps only because I was looking at "lower priced" headers.

I can say, that putting headers on my new motor before it was fully broken in (did start with manifolds, just didn't wait long enough) the effects of ceramic coating on the inside was DRAMATIC. I thought when I first got the Hedman Elites that they were coated on the inside, but that was just leftover from the coating process, and had gone in maybe 3-4" at each port.

In any case, the headers were glowing cherry red after a few minutes of running, but the red hot portion ended right where that overspray was on every cylinder. (so closest to the exhaust port, no red) No hint of heat there whatsoever. If and when I have to replace these headers, I'm going to try to find some that are coated inside, or find out if I can have them coated inside. This will also help with the O2 sensor and not having potential problems with needing a heated one.

 

[ryoken]

honestly, i don't know... haven't spoken with Thorley yet... i do know that Jet Hot does.. i've heard it makes a big dif...

when i spoke to Holley i didn't ask. but if i decide on Hookers, i'll get em thru Jet Hot... they seem to be big on Hookers.. never saw thorleys on their list..

the funny thing is, when i called Jet Hot, they have a list of headers in stock.. so i asked if they could get Super Comps, 1 5/8, single AIR and coat them.. they said yes, $610... didn't think that was too bad..

but then i talked to Holley and they said the super comp was no longer available in single AIR or for my truck for that matter. only comps in 4 AIR.. if they had Comps in single AIR, i'd have JetHot get em and coat em. prolly be about 400 for comps as opposed to 610 for supers....

i'm gonna get back on it in a couple weeks... tied up now with the psycho dash job...

 

[4xrick]

i put regular 350 headers on mine and tapped a hole back in the exhaust and installed the o2 after the y and it works fine.

 

[85burbanator]

my thorleys came with spots for the o2 sensor. on the subject or A.I.R.. does the motor need it to run? can i remove mine? its a 90 350 tbi blazer engine. im in michigan and its going to mostly be a trail vehicle.

 

[dyeager535]

I don't know that anyone has come to a consensus about AIR removal on TBI trucks. In cars it was found in the code that there is an "offset" used for the O2 sensor calculations for when AIR is injected, but the truck system may be different.

In any case, lots of people remove AIR on injected vehicles and don't notice any problems. I'm not running AIR with my TPI, but to be honest, since it doesn't run factory perfect, I can't say whether or not that is part of the problem.

 

[ryoken]

when i did my CFM tech stuff, i ditched the AIR temporarily till i go headers. i will put the smog pump back in at that point for NJ emision..

for now, i've noticed no difference at all.. not throwing any codes, etc... i definitely want to maintain my stock 1 fitting AIR tho. i'm sure i could rig up the 4. but its just more clutter.. bad enough i gotta run it all...

 

[Thunder]

The AIR system on FI vehicles only works when the vehicle is cold. It adds air to the exhaust during warmup to burn the excess hydrocarbons from the rich mixture. After the enginewarms up the AIR system just goes into bypass and vents the air. Thats why they have all those vaccum operated valves on those things.
Removing the AIR system will not effect the way TBI and most other FI systems run They may throw some codes. But it wont hurt performance.

 

[dyeager535]

You are incorrect. Go read up on AIR over at Thirdgen.org, and you will see that when the actual coding of the PROM data was interpreted, there was more to AIR than was thought.

AIR was ALWAYS thought to be injected only when cold, and although that may vary based on vehicle, it is not true 100% of the time.

 

[K5Glazier]

I'm running a set of Gibsons, direct bolt on. (shortys) Decent header but not a full header. They are OK, but nothing to brag about. Never felt any kind of gain in performance because my motor was rebuilt at the same time I installed the headers. Being only shortys, I really didn't expect much.

Joe

 

[k5floyd]

ive always heard that ceramic coatings crack and peel off after a while. by a while i mean, like no more than year. anyone ever find out if the ceramic thorleys and coated inside as well?